Soliton versus nonsoliton operation of fiber ring lasers

To date most passively mode-locked erbium-doped fiber laser systems have employed solitons for short pulse generation, and ultrashort high energy pulses have been difficult to achieve. We show that by reducing the system nonlinearity via pulse stretching and employing net positive dispersion cavities, pulses of sub-100-fs duration and ≳100 pJ energy are readily generated. Data are presented for varying net dispersion in a fiber ring.